Darrell Wallace Jr. has long thrived at Kentucky Speedway, winning on the quarter-mile short track while racing a development car before his days as a NASCAR Camping World Truck Series driver.

Wallace, when he was 10 years old or so, walked away from the Sparta track with what's still one of his largest trophies – "a big, coffee-table-sized thing. It's insane."

He returns for Thursday's UNOH 225 no longer an unknown talent from Mobile, Alabama, but rather the rising star everyone just calls "Bubba" – the nickname given to Wallace born by his older sister the day he was born.

Wallace, 20, is in his second year as the only full-time black driver in one of NASCAR's top three divisions – the Sprint Cup, Nationwide and Camping World Truck series – and doesn't mind carrying the flag for the organization's diversity efforts.

That is, so long as there are still checkered flags in his future.

"It's got to be played up, because there's nobody there," Wallace said. "NASCAR is trying to change the face of the sport in multiple ways – not only with African-Americans but Hispanics, youths, women. It's a big category NASCAR is really pushing, and I just happen to be the ambassador.

"I have no problem doing that, and I know the ultimate goal is to go out and win races."

Wallace is NASCAR's fourth black driver to race full-time in a national series, following Wendell Scott, Willy T. Ribbs and Bill Lester. The recently named Hall of Famer Scott was the only one to win a race until Wallace went to victory lane last year at the Martinsville Speedway, 50 years after Scott's 1963 triumph in Jacksonville, Florida.

Wallace then won his second race, the Drivin' for Linemen 200, after leading a race-high 85 of 160 laps June 14 at Gateway Motorsports Park in St. Louis. The truck series took a week hiatus before its trip to Kentucky, though Wallace insists time away from the track has done nothing to squelch his team's momentum.

"It'll be easy to keep it up so long as we keep thinking about it and talking about it the way we have," Wallace said. "Getting a week off lets it sink in for sure. It was such a great weekend for us.

"I've just got to keep my guys pumped up. We've won one and can carry that forward."

Wallace, who drives Kyle Busch Motorsports' No. 54 Toyota Tundra, is the only driver not named Matt Crafton or Kyle Busch to win in seven truck races this season.

He'll have to face the boss, along with the Sprint Cup Series' Brad Keselowski and Austin Dillon, in the UNOH 225.

Busch, who won Kentucky's first Cup Series race in 2011, has also entered Friday's Nationwide Series race, aiming at a weekend sweep.

"We can take a lot from him and bounce ideas off each other," Wallace said.

Wallace's team is bringing a truck in which he finished 10th at Texas. He noted that last year, before getting involved in an early wreck at Kentucky, he was running faster than eventual third-place finisher Busch.

He grew comfortable with the full, 1.5-mile layout – much larger than he raced on in his youth Bandalero car – thanks to a Goodyear tire test before the race.